So I've been working on building my own canister filter for my 125 NPT. The reason is because I wanted a 6' spray bar to provide circulation for the entire tank, thus requiring a pump with some decent flow. Completed my build today and tested it, problem is the bucket I used is too thin and the input flow is to slow.

I originally had a single 3/4" inlet to the filter, and a 3/4" outlet going to my Iwaki MD40RLT pump (I'm guessing about 600-650 GPH after head). Yea, didn't think it through and that 3/4 inlet wont keep up AT ALL Sooo, I had an extra 1/2 bulkhead sitting around and I added that too, still not enough (after some additional research I found the flow rates for those bulkheads are 350 and 150 GPH). The resulting pressure created by the pump sucking the water through the filter was strong enough to warp the bucket's shape while on The bucket I used as a translucent 3.5 gallon from Lowes, looks like it's not going to be strong enough to handle the pressure the canister filter is going to put out.

My idea thus far is to get a heavy duty 5 gallon ( 90 mil thickness as opposed to standard 70 mil on your average plastic bucket), and 2 3/4" bulkheads. The reason I'm trying to stay with the 3/4" bulkheads is because I'm using 5/8" hose to allow me to use the quick disconnects like on a Magnum 350 filter. I have to have disconnects on the input lines so I can disconnect them to spin off the lid to the bucket/filter.

Is it normal for a canister filter to carry pressure inside and have the pump suck the water, unlike a sump that is open? Is 650 GPH too much flow on a 125 NPT?

Any other ideas to help improve the design would be sweet, perhaps someone knows of a larger hose disconnect I can use?

Yes, the pump can collapse the bucket.
You could probably use some other form of disconnect, for example PVC unions. These are available in all the regular PVC sizes. A ball valve above it would hold the water in the pipe so that when you reconnected it would self-siphon and fill the bucket.

650 gph is pretty good filtration for a 125, I would not go any lower, but would probably add a couple of power heads to increase circulation if there are any dead spots.

When you consider the consequences of a major failure of a DIY canister filter I think it isn't a good project to tackle. Why not look at one of the Ocean Clear filters, http://www.aquariumguys.com/oceanclear.html which many people use and like? At least you could use this as a "blueprint" for how to design a good one.

I didn't know about those filters for many years. I think the first time I realized what they were was about 2 years ago. There are two brands of them, as far as I know, but I don't know what the other brand is.

Register Now

In order to be able to post messages on the The Planted Tank Forum forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:

Password

Please enter a password for your user account. Note that passwords are case-sensitive.

Password:

Confirm Password:

Email Address

Please enter a valid email address for yourself.

Email Address:

OR

Log-in

User Name

Password

Remember Me?

Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.